In the field of advertising, it is well known that billboards are used to display one or more images to passersby. It is also well known that the cost of renting a billboard may be prohibitive for some would-be advertisers. Thus, the use of billboards is commonly becoming divided between several renters. For instance, the area defined by the billboard within which advertisements may be displayed may be subdivided into several regions, with each region being rented by a single advertiser. This practice is especially common with retailers in common shopping areas such as at outlet malls.
Another method of subdividing a billboard is to provide a plurality of vertically oriented multi-faceted units aligned such that a complete image is displayed by the combination of the displayed faces of each individual unit. In order to change the displayed image, each of the units is rotated. Thus, another face of each unit is displayed and, in combination with the other newly-displayed faces, the new image is displayed.
Each of these methods are limited in the number of advertisers which may utilize a single billboard. Specifically, the subdivided billboard wherein several advertisements are displayed simultaneously is limited by the size. Typically, no more than three or four advertisers may effectively use this billboard. In the second instance, the multi-faceted units typically define no more than three faces. Thus, only three display screens are possible. If one were to combine both of these embodiments, there would still be a maximum of approximately twelve advertisers.
Another method used to display a variety of images is to project an image onto a screen using a conventional projector such as a slide projector. The images may be changed by advancing the projector tray. In conventional home projector systems, up to 140 slides, and conceivably more, may be viewed in a single slide tray. Typical devices which have been developed to display advertisements or other signage using various types of projectors are disclosed in the following U.S. Patents:
______________________________________ U.S. Pat. No. Inventor(s) Issue Date ______________________________________ 1,798,078 R. Geyling, et al. Mar 24, 1931 3,198,066 C. L. McGhee Aug 3, 1965 3,552,845 C. Yates, Jr. Jan 5, 1971 5,140,301 Y. Watanabe Aug 18, 1992 ______________________________________
Of these patents, the Watanabe ('301) device is designed to project a laser beam onto a doorway in the event of an emergency. The laser beam is provided for directing occupants out of a building in the event of an emergency. This type of signage is well known to be expensive to operate for extended periods of time. Further, the images displayed by a laser beam are insufficient as an independent image source to display an advertisement of a typical size and intricacy.
The Yates, Jr. ('845) device is a portable display device used for back-projecting an image toward a screen for viewing on an opposite side. The projector is enclosed within a housing closed at one end by the screen. The enclosure is provided with a temperature control to enable the projector when the inside temperature of the enclosure is within a pre-determined temperature range. A heater and a fan are both provided to maintain the operating temperature. A light sensitive element is provided to permit operation only in the darker hours of the day, as sunlight interferes with the projection of an image on the screen. However, this type of projector system cannot be economically used in conjunction with conventional billboard configurations. Specifically, the enclosure wherein is located the projector is expensive to manufacture and maintain considering the size required in relation to the size of the billboard. Further, considering the type of screen required to display the projected image, the screen can be used only for that purpose. Therefore, the screen is useless during daylight hours.
Those devices disclosed by Geyling, et al. ('078) and McGhee ('066) provide at least one projector for projecting images onto a display surface. The Geyling invention is specifically directed toward a projection surface which prevent undesirable ambient light from impinging upon the display surface. The Geyling device also allows wind to pass therethrough by dividing the screen into a plurality of swinging panels. Geyling, et al., do not disclose the operational characteristics and control of the projector.
McGhee provides a photo-electric switch to allow operation of the projector during the dark hours of the day with the images being projected on a blank screen. During the daylight hours, a painted image is displayed. A motorized device is provided for selecting the screen on which the image is to be displayed. In one embodiment, a scroll is provided on which is a blank panel and a painted panel, the motorized unit being used to scroll from one panel to the next at the onset of darkness or daylight. In another embodiment, the screen is composed of a plurality of laterally-disposed, vertically-oriented slats, one side of which is blank, the other side of which is painted. The motorized unit in the latter embodiment serves to rotate the slats 180.degree. to display either of the blank or painted sides. McGhee does not teach the control of the projector unit with the exception of the amount of ambient light present.
None of the prior art disclosed teaches the use of on-site monitoring of operating conditions other than temperature and light. For example, none of the prior art provides for the monitoring of the operation of the projector lamp, the interchanging of slides within the slide carriage, or any other failures which may and will occur. Further, none of the prior art provides for the immediate contact of maintenance and/or police in the event of vandalism or some other situation which would require immediate attention. Further, the prior art is void in teaching the ability to control the operation of the projector from a remote location such as to alter the display sequence and duration of the various images.
Therefore, it is an object of this invention to provide a means for displaying a sequence of images onto a display surface such as a billboard while also providing means for monitoring the working environment of the projector.
It is also an object of the present invention to provide a means for alerting appropriate personnel as the occurrence of any selected event which interferes with the normal operation of the projector and control system.
Further, it is an object of the present invention to provide a means for controlling the functions of the projector from a remote location, those functions including, but not limited to, the display sequence and duration of the individual images.